Projector-carbon.



J. F. KERLIN.

PROJECTOR CARBON.

APPLIOATION FILED JAN.8,1912.

1,065,141, Patented June 17, 1913.

. WITNESSES INVENTO? ATTORNEY UNITED STATES PATENT OFFICE.

JOHN F. KERLIN, OF LAKEWOOD, OHIO. ASSIGNOR TO THE NATIONAL CARBON (30., OF CLEVELAND, OHIO, A CORPORATION OF NEW JERSEY.

PROJECTOR-CARIBON.

Specification of Letters Patent.

Patented June 1'7, 1913.

1nain stationary in one place, but moves around the end of the carbon. In ordinary street lighting this feature is not very objectionable, but in moving picture apparatus it is important to hold the arc steady .1n order to produce uniform projections.

My mvention is therefore particularly adapted to projector carbons for moving picture machines although it can be used to advantage in any are light.

I have found that if a furrow or small groove is made lengthwise of the carbon that the arc will remain approximately sta tionary. If this groove is made V shaped the carbon quite often cracks through to the core when it is baked in the furnace.

To overcome this difficulty I make the groove with a rounded bottom so that there is no sharp corner to start a crack.

In the drawing the single figure shows a.

cored carbon 1 having a core 2, filled with are sustaining material. Throughout the length of this carbon is formed a groove 3, having a rounded bottom 4.

Carbons made in accordance with my in vention maintain a steady arc of unchanging position, and will not crack when baked in the electric furnace.

While I have shown my improvement as being applied to a cored carbon it. is not limited to this type as it could be used with solid carbons or with other types.

Having described my invention, what I claim is:

An are light carbon having a core therein and a groove or furrow in the carbon extending parallel to the core, said groove or furrow having a rounded bottom whereby the carbon will not crack when baked.

In testimony whereof I have hereunto signed my name.

JOHN F. KERLIN. W'itnesses:

A. G. SUMMERELL, A. B. PYKE. 

